The present invention relates to a coin discrimination apparatus for discriminating coins inserted in an automatic vending machine or a public telephone set.
A conventional coin discrimination apparatus is disclosed in U.S. Pat. No. 3,918,565 issued on Nov. 11, 1975. According to this apparatus, physical characteristics such as the thickness and outer diameter of a coin are detected as electrical signals by a detector. At the same time, upper and lower limit values corresponding to the detection signals of the physical characteristics are stored in a memory. The upper and lower limit values are compared with the detection values, respectively, thereby discriminating authenticity and denomination of the coin.
According to this conventional technique, data representing the upper and lower limit values of the physical characteristics of coins corresponding to the denominations must be read out from the memory, and all the readout data must be compared with the corresponding detection signals, thus failing to achieve high-speed operation and increasing power consumption. In addition, when the above operations are performed by a processor, a program is complicated, and a time margin for other control operations is decreased. Since high-speed discrimination cannot be performed, the discrimination time is increased to limit the time interval for coin insertion. The coin path design is limited, resulting in inconvenience.